In the wake of Katy Perry and Russell Brand's, we're celebrating the day of love with a look back at some past couples that seriously raised eyebrows. Although most are now history, a few are still going strong. We're talking to you, Katie Holmes and Tom Cruise.

From McCaulay Culkin and Mila Kunis to Michael Jackson and Lisa-Marie, here are 20 celebrity couples that made us do a double take.